Cooling Flows through an Annulus Pipe in a Non-Intrusive StressMonitoring System (NSMS) Probe pdf download.This paper describes the development of a mathematical model based on equationsfor compressible pipe flow,convective heat transfer,and conductive heat transfer.The model is then applied to the cooling flow through a Non-Intrusive Stress MonitoringSystems(NSMS)probe,to determine the effectiveness of the coolant flow.
NSMS,uses optical probes to record the stress in the rotating blades of a jet engine.
The maximum operating temperature for a NSMS probe is 350F.This poses a problem since the probe is installed in a jet engine where flow path temperatures can reachupwards of 3600F.The only way to maintain the operability of the probe is to cool it.This study focuses on the effectiveness of the required cooling flow at various massflows and various environmental temperatures.The cooling flows will be looked at indepth using AFT Arrow [1]，a program for comprehensive compressible pipe flow analysis.
The flow analysis will be preformed by modeling the typical supply line for a NSMS probe,and using the typical cooling medium of gaseous nitrogen.The typicalcooling line has an inner diameter of 0.187in and is comprised of a braided stainlesssteel cable with an inner Teflon liner.Within the supply line there is a stainless steel 0.125in outer diameter hypo tube which contains the optical fibers.In order to get theleads out of an engine the supply line and hypo tube assembly is typically around 20ft long.